US8147158B2

Travel multiplier mechanisms for writing instruments

Summary by NHIP

Travel multiplier writing instrument

The writing instrument uses a cam member to multiply the travel distance of a sliding piston relative to a push button. The pivot axis lies outside the barrel, and the cam pivots about this axis while engaging an angled surface on the piston.

Claim Score by NHIP

Read claim 1, the broadest

Abstract

A writing instrument includes a travel multiplier mechanism that includes a cam member that pivots about a pivot axis in response to motion of a push button member. The cam member engages a sliding piston member in order to provide a travel multiplying effect such that a distance of travel of the sliding piston member exceeds a distance traveled by the push button member.

US8147158B2, drawing sheet 1
Sheet 1 of 16

Term

Term ended

Expired 2 February 2026, 0.6 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

20 claims: 3 independent, 17 dependent

  1. 1
    Broadest claimClaim Score 72, broad(NHIP)A writing instrument comprising:a barrel;a push button member disposed in the barrel and movable between an extended position and a retracted position;a cam member that pivots about a pivot axis in response to movement of the push button member from the extended position to the retracted position, the pivot axis being located outside of the barrel;and a sliding piston member that is engaged by the cam member and configured such that a distance of travel of the sliding piston member exceeds a distance traveled by the push button member when the push button member is moved between the extended position and the retracted position.
  2. 11
    A writing instrument comprising:a barrel;a clip member coupled to the barrel;a push button member disposed in the barrel and movable between an extended position and a retracted position;a cam member secured to the clip member and adapted to pivot about a pivot axis in response to movement of the push button member from the extended position to the retracted position;and a sliding piston member that is engaged by the cam member and configured such that a distance of travel of the sliding piston member exceeds a distance traveled by the push button member when the push button member is moved between the extended position and the retracted position.
  3. 20
    A writing instrument comprising:a barrel having a primary axis;a clip member coupled to the barrel and defining a cavity with a cylindrical portion;a push button member disposed in the barrel for linear movement along the primary axis between an extended position and a retracted position;a cam member including a cylindrical part secured in the cylindrical portion of the cavity of the clip member and adapted to pivot about a pivot axis in response to movement of the push button member from the extended position to the retracted position, the pivot axis being located outside of the barrel;and a sliding piston member that is engaged by the cam member and configured such that a distance of travel of the sliding piston member exceeds a distance traveled by the push button member when the push button member is moved between the extended position and the retracted position.